OHM V-2 Rocket

[OrbitHangar]

Author: vsfx

The V-2 was the first and is perhaps the most infamous rocket missile in history.

Three scenarios are included with different launch sites, rocket paint schemes, V-2 specifications and flight objectives.
 
-1944 V-2 Peenemunde
-1945 V-2 Target London
-1946 V-2 White Sands

Expanded scenario details and flight instructions given in .pdf readme.

The performance and capabilities of the rocket have been simulated and tested as accurately as possible using Spacecraft3.

Image: White Sands V-2 Sounding Rocket

YouTube video: http://www.youtube.com/watch?v=un0dCSG_3kI
 
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INSTALLATION
 
Extract / copy all of the folders and files from the .rar archive into your Orbiter main directory.
 
Also requires Spacecraft3 by Vinka.
 
A base called “Target London” will be installed which is located at the Houses of Parliament in central London.

 
* * * *
 
Enjoy these pioneering flights!

You are free to re-use, edit, re-distribute all material herein.


DOWNLOAD

 

[vsfx]

Had some fun with the White Sands scenario re-creating the first ever images from space taken by captured German V-2s.

This is the real first ever photograph from space taken back in 1946.

These are Orbiter images (taken using [ame="http://www.orbithangar.com/searchid.php?ID=3279"]Screen capture[/ame]) from a 160km apogee V-2 flight edited with Photoshop Elements to give the 1946 look (B&W, contrast, grain, posterization). I think the first one looks similar to the real image, except for the clearer skies.

 

[Urwumpe]

Too bad that still no DLL version of the V-2 is around...or the various support vehicles and panels for launching one realistically.

The German army manual ("A4-Fibel") for the V-2 is available as 55 MB PDF.

http://www.aggregat4.de/A4_Fibel.html

(Alone recommended because of the visual style of the German Army manuals in that period)

And here is also a detailled description of the missile in German as 30MB PDF (more detailled than the "Fibel", but also no humor )

http://www.aggregat4.de/geraetebeschr.html

Ok, it is German, and it uses technical terms of the 1930s, not modern ones, which makes translation a bit harder today.

And the launch preparation schedule ("X-Plan") might be interesting as well:

http://www.aggregat4.de/x-plan.html

 

[Lucy]

Too bad that still no DLL version of the V-2 is around...or the various support vehicles and panels for launching one realistically.

The German army manual ("A4-Fibel") for the V-2 is available as 55 MB PDF.

http://www.aggregat4.de/A4_Fibel.html

(Alone recommended because of the visual style of the German Army manuals in that period)

And here is also a detailled description of the missile in German as 30MB PDF (more detailled than the "Fibel", but also no humor )

http://www.aggregat4.de/geraetebeschr.html

Ok, it is German, and it uses technical terms of the 1930s, not modern ones, which makes translation a bit harder today.

And the launch preparation schedule ("X-Plan") might be interesting as well:

http://www.aggregat4.de/x-plan.html

You have the skill and capacity, and apparently resources, what's stopping you?

 

[N_Molson]

You have the skill and capacity, and apparently resources, what's stopping you?

Totally agree, if someone can simulate that one accurately that's you, Urwumpe. :tiphat:

 

[Urwumpe]

You have the skill and capacity, and apparently resources, what's stopping you?

Problem A: I can't make meshes without giving up after a few days in frustration.

Problem B: I can code it... but have too many projects already for my freetime. I have exceeded my WIP limit already a few years ago and now have to cut back, if I should be able to get anything done at all. I am no Kev33, who can release 20 add-ons per month.



Thus my rather direct attempt for making it easier for others to pick it up.

You are right if you say that I am one of the best candidates around in the forum for this project, because I can develop Orbiter modules and live on the right side of the possible language barrier for understanding the documents. But I don't think I am a good choice right now.

 

[N_Molson]

"Kanban" will be a great name for my next KSP vehicle :lol:

Yeah, Kev33 was impressive, especially at meshing-texturing.

 

[boogabooga]

Too bad that still no DLL version of the V-2 is around...

Uhhh....

Have you seen this:
[ame="http://www.orbithangar.com/searchid.php?ID=2647"]V2 by igel[/ame]

No ground operations, true. But simulated guidance and failures. Plus a great GE interface. Works fine for me in Orbiter2010.

 

[Urwumpe]

Uhhh....

Have you seen this:
V2 by igel

No ground operations, true. But simulated guidance and failures. Plus a great GE interface. Works fine for me in Orbiter2010.

Must have missed it... but no launch platform as well... but seems to fly right. Spacecraft3 isn't really good for simulating rockets with TVC.

 

[4throck]

...

http://www.aggregat4.de/A4_Fibel.html

(Alone recommended because of the visual style of the German Army manuals in that period)...

Can only look at pictures, but indeed loved the design. And yes, detailed panels and rocket schematics.



As for the SC3 limitations, I guess we are talking tailfins / aero-stabilization /guidance ?
If so, I have experience in using LUA to improve those aspects (I did it with the Brazilian VS-40), so it might be "simple" to implement.

 

[Urwumpe]

As for the SC3 limitations, I guess we are talking tailfins / aero-stabilization /guidance ?

Tail fins and thrust vanes, just like the A4 derived Redstone rocket.

 

[BruceJohnJennerLawso]

Tail fins and thrust vanes, just like the A4 derived Redstone rocket.

Redstone still looked nicer IMO. Always liked it, even if it was almost useless as a real launcher.

 

[4throck]

Ok, but what exactly is missing from the vehicle behaviour? I mean, I throttle up and the rocket ascends on a convincing arc. It looks OK to me..

Should some roll be induced, is that it?

 

[Urwumpe]

Ok, but what exactly is missing from the vehicle behaviour? I mean, I throttle up and the rocket ascends on a convincing arc. It looks OK to me..

Should some roll be induced, is that it?

No, it simply has too much thrust available since no engine thrust is used for the rotation and also consumes too much fuel for the rotation. That is the limitation of Spacecraft3, that RCS is simplified and main engine thrust direction fixed. Also, on a lesser factor, the different attachment locations of the forces also have a small effect on the flight behavior, but none that you would really notice... who has ever flown a manned V-2? These wrong torques are just interesting from an engineering POV, but the external performance is pretty different to the real one in spacecraft3.

 

[4throck]

I get it. When I did my LUA enhanced VS-40, I disabled the RCS completely, because that rocket was aero-stabilized and had no guidance.

I realize that the V2 is more complicated than that. From wikipedia:

The V-2 was guided by four external rudders on the tail fins, and four internal graphite vanes at the exit of the motor. The LEV-3 guidance system consisted of two free gyroscopes (a horizontal and a vertical) for lateral stabilization, and a PIGA accelerometer to control engine cutoff at a specified velocity. The V-2 was launched from a pre-surveyed location, so the distance and azimuth to the target were known. Fin 1 of the missile was aligned to the target azimuth.[24] Some later V-2s used "guide beams", radio signals transmitted from the ground, to keep the missile on course, but the first models used a simple analog computer that adjusted the azimuth for the rocket, and the flying distance was controlled by the timing of the engine cut-off, "Brennschluss", ground controlled by a Doppler system or by different types of on-board integrating accelerometers. The rocket stopped accelerating and soon reached the top of the approximately parabolic flight curve.

Now this only makes sense if we are replicating the guidance system. What interaction would there be for the user? Define cut-off velocity and Azimuth?
It seems that the flight curve was constant, only the cut-off changed.

 

[Urwumpe]

Now this only makes sense if we are replicating the guidance system. What interaction would there be for the user? Define cut-off velocity and Azimuth?
It seems that the flight curve was constant, only the cut-off changed.

From what I had found out last night while tagging the system description of the V-2, the flight curve was only constant for the military versions, but you had been able to modify it before flight by installing different resistors in the sequence controller. The resistors controlled the speed of a small DC electric motor, that tilted the D gyroscope in the D (elevation) axis.

The thrust vanes had also been pretty special in their arrangement, as every gyroscope controlled only one pair of vanes. The EA gyroscope (yaw and roll) one, the other was controlled by the D gyroscope (elevation). I am not yet sure how this worked out, but the drawings are conclusive there (Had axes mixed up in their meaning: they only make sense when the missile is standing upright on the launch pad).

The pitch program ran from 4 to 52 seconds and had 8 sections, that had one fixed pitch rate for that section. From 52 seconds on, the pitch was kept constant (in gyroscopic coordinates: No correction for the curvature of Earth = a slow pitch up during the final seconds of the burn)

So, you essentially only set the cut-off velocity, and rotate the missile to the right azimuth. Azimuth is set by the launch table, cut-off velocity by either rotating a large wheel in the electronics section (behind an access door) or by a smaller wheel in the radio control van (if you used radio control).

 

[4throck]

Thanks for the investigation :yes:

So basicly the guidance system is aerodynamic + thrust vectoring.
Do you think it could be simplified in Orbiter by manipulating the angular velocity ?
Do we have any data for that? Something like maximum rotation rates or something.
If we just use arbitrary values, it defeats the point of simulation I think.

I still think it can be done in LUA, simply manipulating the behaviour provided by SC3.

 

[Urwumpe]

Thanks for the investigation :yes:

So basicly the guidance system is aerodynamic + thrust vectoring.
Do you think it could be simplified in Orbiter by manipulating the angular velocity ?
Do we have any data for that? Something like maximum rotation rates or something.
If we just use arbitrary values, it defeats the point of simulation I think.

I still think it can be done in LUA, simply manipulating the behaviour provided by SC3.

Looking for it, but the behavior seems to be a bit more complex... there are two rudders on the fins for compensating roll I think... need to look at this again once I have been running my 3 miles today

 

[4throck]

No rush. Even if nothing comes out of it, we can add the info to the wiki. It's the sort of thing that belongs there, I think.

Here's some hard data from Wikipedia, about the sound rocket version (the one I like...):

"The fuel was consumed in the first minute of flight producing a thrust of 56,000 pounds-force (250 kN). Maximum acceleration of 6 Gs was reached at minimum fuel weight just before burnout, and vibrational accelerations were of similar magnitude during powered flight. Velocity at burnout was approximately 5,000 feet (1,500 m) per second. The rocket would typically have a small, unpredictable angular momentum at burnout causing unpredictable roll with pitch or yaw as it coasted upward approximately 75 miles (121 km). A typical flight provided an observation window of 5 minutes at altitudes above 35 miles (56 km)."

 

[Urwumpe]

No rush. Even if nothing comes out of it, we can add the info to the wiki. It's the sort of thing that belongs there, I think.

I would say you are right. Wikipedia is pretty limited on the V-2 technology. Even the German one could be improved.

And astronautix has a wrong value in its data... the ISP of the production model is not 203 seconds (1991 m/s), but had been 2250 m/s or 229s according to later sources, while the description still talks of 2000 m/s exhaust velocity.